High security cross-cut shredders, suitable to shred "Classified" and "Top Secret" documents. Carbon hardened cutting knives. High precision design of cutting knives allows high shred loads with low power consumption. 24 hours continuous duty motor: no duty cycle or timed cool down period. HS-6 model can shred a paper sheet in about 20.000 microchips which become unreadable even if special electronic devices are used.